Understand when I said Friday seems to be the lightest of the Easter time days that just means it is not quite as bad as the other days which are all hugely crowded. Everytime we have gone at the time of year, Good Friday has always seemed less than other days (why is anybody's guess), but what that means is that people are not quite completely on top of each other and the popular rides don't get up to a 2 hour line for as long a period in the day as other days. In other words, trying to chose a truly "light" day for MK during that time of year is a futile exercise as there is no such animal. MK will be extremely packed everyday and some days, like Easter Sunday, are just even worse than the rest. Whether Florida schools are in or out of session is entirely irrelevant to that time of year. In fact, you will find that most local residents avoid WDW like the plague during those weeks. The crowds are produced by the huge numbers of out of state guests who have spring break during those Easter weeks.